( cxxviii ) 



lifetime, and thus are always "prior to individual experience."* 

 The behaviour which leads to the production of an elaborate 

 cocoon or the burial of a larva in its earthen cell is clearly 

 instinctive, and the most convincing evidence would be re- 

 quired — evidence which it is needless to say is entirely lacking 

 — in order to prove that certain insects which perform an act 

 no more elaborate many times in their lives are guided by 

 anything except the compulsion of a " nervous system built 

 through heredity." f If the cocoon-making instinct has evolved 

 through selection, the comb-making instinct of the social 

 Hymenoptera has surely arisen in the same way and not 

 through the operation of an entirely different set of causes. 



As a matter of fact I have witnessed the perfection of comb- 

 building " prior to individual experience " and under con- 

 ditions which prevented the worker from profiting by the 

 experience of others. I have seen " the worker of a species of 

 Vespa freshly emerged from the pupa, and the sole perfect 

 insect upon the young comb (the queen-mother having been 

 previously killed), immediately seize upon the broken material 

 of the comb and begin accuiately and with exact precision to 

 build up the thin and delicate sides of injured cells containing 

 the living larvse." J 



The strongest of all arguments against Lamarckian evolu- 

 tion was advanced nearly fifty years ago by Darwin in the 

 first edition of the " Origin of Species " ; and here too we see 

 that demonstrative evidence was supplied to the greatest of all 

 naturalists by reflection upon the insect world, and of the part 

 of it which we are now considering. " No amount of exercise, 

 or habit, or volition," he says, speaking of ants, " in the utterly 

 sterile members of a community could possibly have affected 

 the structure or instincts of the fertile members, which alone 

 leave descendants. I am surprised that no one has advanced 

 this demonstrative case of neuter insects against the well- 

 known doctrine of Lamarck." § 



* For instance, the cocoon-making instinct, ah'eady alluded to (see 

 pp. cxx-cxxiii). Weismann has directed particular attention to this 

 argument against a Lamarckian interpretation ("The Evolution Theory," 

 London, 1904, pp. 155 ct seqq.). 



t "Nature, "vol. Ixv, 1901, p. 51. The jjassage has been slightly modified. 



+ ;. c, p. 50. § " The Origin of Species," London, 1859, p. 242. 



